3.4 Label Lines

Label lines begin with the ampersand, ‘&’:

& SGR: SELECT GRAPHIC RENDITION

Label lines always describe a control function, and are always
preceded by the escape sequence that invokes that function (unless the
-E option was given, suppressing output for escape-sequence
lines).

The format of a label line’s content is always acronym:
name; both of these are defined for each control function
by
Ecma-48 / ISO/IEC 6429. In some cases, they may also name private functions
defined by popular terminals and terminal emulators.

Label lines currently are never wrapped; however, future
versions of Teseq may wrap label lines. At that time, continuation
label lines will probably consist of an extra space after the
ampersand (similar to how escape-sequence lines are wrapped). Lines
will never be split in the middle of a word.

Future versions of Teseq may use label lines to describe things besides
escape sequences; for instance, control characters or control strings,
or other strings that may be interpreted specially by some devices or
applications.